HWLOC-GATHER-CPUID(1)

💅 HWLOC-GATHER-CPUID(1) — the hwloc manual page, bestie edition

okay so real quick — this is hwloc-gather-cpuid from the hwloc manual, section 1. if you're on x86 and you want to snoop on your CPU's whole personality, congrats, you're in the right place 🎀

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✨ NAME ✨

hwloc-gather-cpuid — dumps all the relevant x86 cpuid values so you can use them later, possibly even offline 🦋

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🌸 SYNOPSIS 🌸

hwloc-gather-cpuid [options] [<outdir>]

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💖 OPTIONS 💖

• -c <idx> — only gather cpuid values for the logical processor whose OS/physical index is <idx>. one PU only, pick your fave 💅
• -q, --quiet, -s, --silent — do NOT show verbose messages. stealth mode, no yapping 🤫
• --version — report the version and dip. that's it, that's the whole job ✨
• -h, --help — display the help message and exit. classic, iconic, helpful 🫶

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🦋 DESCRIPTION 🦋

so hwloc-gather-cpuid dumps all the relevant x86 cpuid values into a subdirectory called cpuid inside the current directory — or into <outdir> if you specified one. no cap, that's the whole vibe 🌈

these files are literally made to be used later, so you can explore the machine topology offline. how? for instance by setting the environment variable HWLOC_CPUID_PATH to the directory that contains all the output files, and by forcing the x86 backend with HWLOC_COMPONENTS=x86,stop. iykyk 🔥

you can also slide the directory contents to the hwloc developers so they can debug issues remotely. remote debugging era 💜

if you use - as <outdir>, the output gets dumped to standard output — but a unique logical processor must have been given with -c. like, you have to pick one, no exceptions bestie 😭

hwloc-gather-cpuid is an x86 specific tool. it cannot be used on other platforms. periodt. 💀

NOTE: hwloc-gather-cpuid gathers many hardware details about the platform. output files should not be posted on public lists or websites unless it is clear that they contain no sensitive information. seriously, do a vibe check before you post 🙈

NOTE: the output of hwloc-gather-cpuid is included in the tarball saved by hwloc-gather-topology on Linux/x86. cute, right? 🍓

NOTE: it is highly recommended that you read the hwloc(7) overview page before reading this man page. homework first, bestie 📚

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🎀 EXAMPLES 🎀

to store cpuid information of all logical processors of the current machine:

$ hwloc-gather-cpuid
Gathering in directory ./cpuid ...
Gathering CPUID of PU P#0 in path ./cpuid/pu0 ...
Gathering CPUID of PU P#1 in path ./cpuid/pu1 ...
Gathering CPUID of PU P#2 in path ./cpuid/pu2 ...
Gathering CPUID of PU P#3 in path ./cpuid/pu3 ...
Summary written to ./cpuid/hwloc-cpuid-info

look at it go, one PU at a time, main character energy 👑

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⭐ RETURN VALUE ⭐

upon successful execution, hwloc-gather-cpuid will exit with the code 0. slay ✨

hwloc-gather-cpuid will return a nonzero exit status if any kind of error occurs — such as (but not limited to) failure to create the output files. so like, if it flops, it flops loudly 😭

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🌈 SEE ALSO 🌈

hwloc(7), hwloc-gather-topology(1), lstopo(1)

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and that's the page, bestie 💖 this was hwloc-gather-cpuid(1) from the hwloc manual — version 2.15.0, dated Sep 23, 2026. go gather some cpuid, ily, bye 🫶🎀